Behaviour of the exhaust valve cladding face under the service conditions

• Autorzy: Kończewicz W. , Smoleńska H.
• Języki publikacji: EN

Abstrakty

EN

During the ship engine operation one of the key problems is the exhaust valve durability. A special interest is in valve head face because this narrow part of the valve is responsible for tightness. Cobalt base laser cladding layer on the exhaust valve head face have been investigate under real service condition using the laboratory two-stroke diesel engine L22 for two years. During this time the engine was fuelling with both ordinary light fuel and biodiesel fuel. After removing from the valve head from the cylinder head the face surface were fully inspected optically. There were no damages and the surface was shining in the great deal however some dark "spots " on it. The samples made of the used valve head underwent microstructural investigation and hardness measurements. There were no observed substantial microstructural changes neither in the surface of the layer nor in the bulk of the clad. The decrease of the hardness numbers was observed but still clad layer presented higher hardness than steel base. This type ofclad layer underwent intensive laboratory examinations which contained oxidation experiments at different temperatures and corrosion in exhaust gases and with the present service experiment this method of valve head hard facing is suitable for practical applications.

Słowa kluczowe

EN

exhaust valve; laser cladding; cobalt alloy; service wear

• Wydawca: Łukasiewicz Research Network - Institute of Aviation ; European Science Society of Powertrain and Transport KONES Poland ; Wydawnictwo Instytutu Technicznego Wojsk Lotniczych
• Czasopismo: Journal of KONES
• Rocznik: 2009
• Tom: Vol. 16, No. 1
• Strony: 265--271
• Opis fizyczny: Bibliogr. 8 poz., rys.

Twórcy

autor

Kończewicz W.

autor

Smoleńska H.

• Gdynia Maritime University, Department of Mechanical Engineering Morska 83, 81-225 Gdynia, Poland tel:[phone]; fax: [phone],

Bibliografia

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• [3] d`Oliveira, A. S. C., da Silva, P. S. C. P., Vilar, R. M. C., Microstructural features of consecutive layers of Stellite 6 deposited by laser cladding; Surface and Coatings Technology 153, 2002.
• [4] Elliott, P., Choose materials for high-temperature environments, Chemical Engineering Progress, 97, 2, pp. 75-85, 2001.
• [5] Schlager, D., Theiler, C., Kohn, H., Protection against high temperature corrosion with laser welded claddings, applied and tested on exhaust valve discs of large diesel engines burning heavy fuel oil, Materials and Corrosion 53, pp. 103-110, 2002.
• [6] Smoleńska, H., The gas corrosion of the cobalt base layer at elevated temperature, Journal of Achievements in Materials and Manufacturing Engineering, Vol. 18, iss. ½, pp. 235-238, 2006.
• [7] Smoleńska, H., Kończewicz, W., Analiza własności napawanych laserowo powierzchni przylgni zaworów wylotowych silników okrętowych po korozji w powietrzu i gazach spalinowych, Inżynieria Materiałowa, R. 27, nr 3/151, pp. 536-539, 2006.
• [8] Kończewicz, W., Smoleńska, H., The resistance investigation of the marine engine exchaust valve using the modelling chamber, Journal of KONES: Powertrain and Transport, Vol. 15, nr 4, pp. 255-262, 2008